A BigLaw partner has sued the Office of the Comptroller of the Currency seeking $4 million in damages.

Carlos Loumiet claims he was maliciously prosecuted on civil regulatory charges in retaliation for a complaint he made to the federal agency’s inspector general about the manner in which an investigation of then-client Hamilton Bank was being conducted, the Daily Business Review reports.

Loumiet is a partner of Greenberg Traurig who represented Hamilton Bank at the time of the incidents at issue. He was accused by the OCC of helping to cover up conduct at the Miami financial institution—before it was shut down in 2002—that eventually put its former chief, Eduardo A. Masferrer, in prison. However, Loumiet pointed out that he was simply one of a number of attorneys working on an independent investigation of the bank, and the OCC eventually dropped the case.

In the suit, which was filed earlier this year in federal court in Washington, D.C., Loumiet contends that both the OCC and individual investigators sought to pay him back for his criticism of their work by making it impossible for him to represent banking clients, his area of expertise.

“It’s outrageous the way the OCC chased Carlos Loumiet,” attorney Andres Rivero of Rivero Mestre, who represents him, told the Daily Business Review. “We are going to prove they violated his constitutional rights. They tried to punish him because he blew the whistle on them.